1. Field of the Invention
The present invention relates to a vehicle equipped with a leanable body frame and two front wheels.
2. Description of the Related Art
A known vehicle includes a vehicle body frame that is leanable leftward or rightward when the vehicle is cornering, and two front wheels that are arranged side by side in a left-right direction of the vehicle body frame (for example, see Japanese Patent Publication No. 2005-313876, German Patent Publication No. 10 2010 052716, U.S. Pat. No. D547,2425, and Catalogo partidi ricambio, MP3 300 ie LT Mod. ZAPM64102, Piaggio).
The vehicle equipped with the leanable body frame and the two front wheels includes a link mechanism. The link mechanism includes an upper cross member and a lower cross member. In addition, the link mechanism includes a right side rod which supports right end portions of the upper cross member and the lower cross member, and a left side rod which supports left end portions of the upper cross member and the lower cross member. Intermediate portions of the upper cross member and the lower cross member are supported by the vehicle body frame in a location directly in front of a steering shaft. The upper cross member and the lower cross member are supported by the body frame so as to turn about axes that extend substantially in a front-and-rear direction of the body frame. The upper cross member and the lower cross member turn relative to the body frame as the body frame leans such that the relative positions of the two front wheels in the up-and-down direction change. The upper cross member and the lower cross member are provided directly above the two front wheels in the up-down direction of the body frame when the body frame is in an upright state.
The vehicle including the leanable vehicle body frame and the two front wheels further includes a right shock absorbing device which supports the right front wheel so as to be movable in the up-and-down direction of the vehicle body frame, and a left shock absorbing device which supports the left front wheel so as to be movable in the up-and-down direction of the vehicle body frame. The right shock absorbing device is supported by the right side rod so as to be turnable about the axis of the right side rod. The left shock absorbing device is supported by a left side rod so as to be turnable about the axis of the left side rod. The vehicle described in Japanese Patent Publication No. 2005-313876 and German Patent Publication No. 10 2010 052716 further includes a handlebar, a steering shaft, and a turn transmitting mechanism. The handlebar is secured to the steering shaft. The steering shaft is supported to be turnable with respect to the vehicle body frame. When the handlebar is turned, the steering shaft also turns. The turn transmitting mechanism transmits the turning of the steering shaft rightward shock absorbing device and the left shock absorbing device.
The vehicle including the leanable body frame and the two front wheels includes many on-board components which are provided on the periphery of the steering shaft. The on-board components include lamps such as a headlamp, a radiator, a reservoir tank, electric components such as a horn, a main switch of the vehicle, a storage box, a storage pocket and the like.
The vehicles described in Japanese Patent Publication No. 2005-313876 and German Patent Publication No. 10 2010 052716 include a resisting force changing mechanism. The resisting force changing mechanism restricts the leaning of the vehicle body frame and a change in relative position of the two front wheels in the up-down direction of the vehicle body frame by increasing a resisting force against the operation of the link mechanism.
In the vehicle described in Japanese Patent Publication No. 2005-313876, the resisting force changing mechanism includes a brake disc and a caliper. The brake disc is fixed to the upper cross member which defines the link mechanism. The caliper changes the resisting force that is exerted on the operation of the link mechanism by controlling the frictional force between the caliper and the brake disc. The caliper is attached to a portion of the vehicle body frame which is located above the upper cross member. The link mechanism operates when the resisting force exerted by the resisting force changing mechanism is zero or small. In the case of the resisting force exerted by the resisting force changing mechanism being large, the operation of the link mechanism is restricted or stopped. In the case of the resisting force exerted by the resisting force changing mechanism being zero or small, the brake disc and the upper cross member move together relative to the vehicle body frame.
In the vehicle described in German Patent Publication No. 10 2010 052716, the resisting force changing mechanism includes a rod, a piston that is provided at one end of the rod, and a cylinder in which the piston moves. In the resisting force changing mechanism, the rod extends or contracts relative to the cylinder as a result of the piston moving within the cylinder. The rod stays stationary relative to the cylinder as a result of the piston being stopped within the cylinder. The other end of the rod is supported by the left rod. The cylinder is supported by the vehicle body frame in a position above the upper cross member. The resisting force changing mechanism operates to change the resisting force against the link mechanism by changing the state of the piston moving within the cylinder. The link mechanism operates when the resisting force exerted by the resisting force changing mechanism is zero or small. When the resisting force exerted by the resisting force changing mechanism is large, the operation of the link mechanism is restricted or stopped. The rod and the cylinder also move as the link mechanism operates when the resisting force exerted by the resisting force changing mechanism is zero or small.
The vehicles described in Japanese Patent Publication No. 2005-313876 and German Patent Publication No. 10 2010 052716 include the link mechanism that is provided on the periphery of the steering shaft, and this link mechanism moves as the vehicle body frame leans. In addition, the vehicles include, on the periphery of the steering shaft, the resisting force changing mechanism which operates as the vehicle body frame leans and as the link mechanism operates. Accordingly, in the vehicle including the leanable vehicle body frame and the two front wheels, the resisting force changing mechanism needs to be provided so that a movable range of the resisting force changing mechanism does not interfere with a movable range of the link mechanism. Further, in providing on-board components, it is necessary that the on-board components are provided so as to avoid interfering with both the movable range of the link mechanism and the movable range of the resisting force changing mechanism. This tends to enlarge the size of a peripheral construction of the steering shaft in a vehicle that includes a leanable vehicle body frame and two front wheels.